1. Field of the Invention
The present invention relates generally to fasteners and, more particularly, to a tool for use with a deformable nut of a fastener.
2. Description of the Related Art
In some fastening circumstances, it is desirable to provide a fastener having a deformable portion that resists loosening or detachment of the fastener. An example of such a fastener might include a structure similar to a bolt and a nut, with the nut being plastically deformable into engagement with the bolt. Examples of such fastening systems are described generally in, for example, U.S. Pat. No. 5,092,726 to Wheeler et al., U.S. Pat. No. 5,061,132 to Cosenza, U.S. Pat. No. 4,742,735 to Stencel, and U.S. Pat. No. 4,544,312 to Stencel.
A deformable nut for use in a fastening system such as that discussed in the aforementioned patents may, for example, include one or more radially protruding structures that can be engaged by a tool to plastically deform the protruding structures and/or other portions of the nut into engagement with a cooperative bolt. An example of such a prior art tool D is depicted in FIG. 1, and an example of a prior art deformable nut H is depicted generally in FIG. 2 in an undeformed condition. The prior art nut H is depicted generally in FIG. 3 in a deformed condition subsequent to deforming engagement by the prior art tool D.
As can be best understood from FIG. 2, the prior art nut H includes a deformable wall L and a number of lugs P. It can be seen that the deformable wall L is generally tapered in an axial direction. When the prior art tool D is received on the prior art nut H and is rotated with respect to the nut H, the lugs P are caused to deform radially inwardly, which results in the deformable wall L being plastically deformed into engagement with, for instance, a shank of a bolt (not depicted) on which the prior art nut H is disposed. It is noted that deformation of the deformable wall L is not depicted in FIG. 3 for purposes of clarity.
As can be understood from FIG. 3, however, deformation of the lug P by the prior art tool D nevertheless results in a portion of the lug P being largely undeformed, such as is shown at the numeral T. The lack of deformation at the region T results from a number of factors including the relative thinness of the deformable wall L at the tapered end being displaced by the lug P during deformation thereof instead of fully deforming the lug P and spreading the material of the lug P into engagement with the shank.
It is thus desired to provide an improved tool that deforms the lugs of a deformable nut to a relatively greater degree than was provided by prior art tooling. It is also desired to provide such a tool that requires relatively less torque to provide the desired degree of deformation.